Chemistry and Industry - Jamb Chemistry Past Questions and Answers

Question 26:

• JAMB 1986

A substance Z reacts with NaOH to give salt and water only. When Z is treated with dilute HCl, a gas is evolved which gives a yellow suspension on passing into concentrated H₂SO₄. Substance Z is?

A. NaHS
B. Na₂SO₃
C. Na₂S
D. NaHSO₃

Question 27:

• JAMB 1986

Which of the following is used as an 'anti-knock' in automobile engines?

A. Tetramethyl silane
B. Lead tetra-ethyl
C. Glycerol
D. N-heptane

Question 28:

• JAMB 1986

Which of the following substance is a mixture?

A. Granulated sugar
B. Sea-water
C. Sodium chloride
D. Iron fillings

Question 29:

• JAMB 1987

Which of the following gases can best be used for demonstrating the fountain experiment?
i) Nitrogen (ii) Ammonia (iii) Nitrogen (I) oxide
(iv) Hydrogen chloride.

A. Ii and iii
B. I and iii
C. Ii and iv
D. Ii only

Question 30:

• JAMB 1987

When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?

A. Bubbling it through concentrated H₂SO₂
B. Bubbling it through water and then passing it through calcium oxide
C. Passing it directly through calcium oxide
D. Passing it directly through calcium chloride